199815258049 has 9 divisors (see below), whose sum is σ = 219637052131. Its totient is φ = 181645764520.

The previous prime is 199815258031. The next prime is 199815258061. The reversal of 199815258049 is 940852518991.

The square root of 199815258049 is 447007.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 481583025 + 199333675024 = 21945^2 + 446468^2 .

It is not a de Polignac number, because 199815258049 - 2⁷ = 199815257921 is a prime.

It is a super-2 number, since 2×199815258049² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199815258649) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4896759 + ... + 4937395.

Almost surely, 2^199815258049 is an apocalyptic number.

199815258049 is the 447007-th square number.

199815258049 is the 223504-th centered octagonal number.

It is an amenable number.

199815258049 is a deficient number, since it is larger than the sum of its proper divisors (19821794082).

199815258049 is an frugal number, since it uses more digits than its factorization.

199815258049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81296 (or 40648 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 61.

The spelling of 199815258049 in words is "one hundred ninety-nine billion, eight hundred fifteen million, two hundred fifty-eight thousand, forty-nine".